OAuth
An authorization framework that lets users grant third-party apps limited access to their accounts without sharing passwords. Powers 'Sign in with Google.'
What is OAuth?
An authorization framework that lets users grant third-party apps limited access to their accounts without sharing passwords. Powers 'Sign in with Google.'
OAuth is a intermediate-level concept that sits in the Security Architecture area of system design. Engineers reach for it whenever they need to reason about real-world trade-offs in that space — not just for textbook correctness, but because real production systems at companies like Netflix, Amazon, and Google make these decisions every day.
If you want to go deeper than this definition — with diagrams, code, and a quiz to lock it in — work through the "OAuth" lesson linked below. It walks through the why, the mechanism, the trade-offs, and how the giants actually use it in production.
Learn OAuth in depth
Full interactive lesson with diagrams, code examples, real-world references, and a quiz.
Open the OAuth lessonRelated lessons
Lessons that touch on OAuth as part of a larger topic.
See also
Related glossary terms you might want to look up next.
JWT
JSON Web Token: a compact, self-contained token for transmitting claims between parties. The server can verify it without a database lookup.
SSL/TLS
Cryptographic protocols that encrypt data in transit between client and server. TLS is the modern successor to SSL. The 'S' in HTTPS.
Session
A way to maintain state across multiple HTTP requests. The server stores data about a user and gives them a session ID (usually in a cookie).